Saturday 15 June 2013 05.42 EDT
First published on Saturday 15 June 2013 05.42 EDT

Britain should arm the Syrian rebels and consider imposing a no-fly zone over Syria to prevent "catastrophic consequences", Tony Blair has said.

The former prime minister said the use of chemical weapons by the Syrian government and the involvement of Iran in the civil war meant intervention was necessary.

"You've got the intervention of Hezbollah, at the instigation of Iran. The other big change is the use of chemical weapons. Once you allow that to happen – and this will be the first time since Saddam used them in the 1980s – you run the risk of it then becoming an acceptable form of warfare, for both sides," he told the Times.

This week the US said it would arm Syrian rebels after claiming to have evidence that the regime of Bashar al-Assad had used chemical weapons – although it did not reveal its evidence or say when and where the weapons were used.

Discussions are under way between the US and key foreign allies over options for further intervention in the conflict, including a no-fly zone, and are likely to come to a head during the G8 summit in Northern Ireland, when Barack Obama and Vladimir Putin are scheduled to hold bilateral discussions.

Britain has urged the European Union to lift an arms embargo on the Syrian rebels but has not yet decided to transport arms.

Blair said the conflict was no longer a civil war. "We should be taking a more interventionist line. You don't have to send in troops, but the international community should think about installing no-fly zones," he said. "You've got to create the circumstances in which Assad is not able to change the balance of power within the struggle by the use of outside forces."

Blair suggested that regime change in Syria was inevitable. "People are no longer going to accept that a minority ruled the country without the say of the majority. It's exactly the arguments we went through over Iraq," he said.

He also reiterated his criticism of Iran, claiming that the transition across the Middle East was being complicated by the policies of the Islamic republic.

"It's not just trying to acquire nuclear weapons, it's trying to export an ideology and an extremism around the region. They continue to meddle in Iraq. It's a hugely destabilising force. I would be 100% more optimistic about the speed with which the region could change if that Iranian regime weren't there."